This invention relates to an electrostatic apparatus and more particularly to an improved apparatus for cleaning a charge line of a transfer charger for use in an electrostatic apparatus.
The performance of electrostatic apparatuses, such as copying machines or laser beam printers depends on a clearness degree of the developed images on copy sheets. Typically, a substantial high voltage is applied to charge line to transfer the toner from a photosensitive drum to the copy sheets, and the quality of images on the copy sheets are greatly affected by the charges from a charge line of a transfer charger.
A typical transfer process is described with reference to FIG. 1. A first charger 32 and a transfer charger 33 both of which have charge fines are respectively provided above and below a photosensitive drum 31. A developer 34 and a drum cleaner 35 are provided at opposite sides of the drum 31.
In operation, the photosensitive drum 31 is rotated above the transfer charger 33, and copy sheets pass over the transfer charger 33. The residual toner remaining on the drum 31 is removed by the drum cleaner 35.
In the typical electrostatic machine, the charge line is likely to be contaminated due to the residual toner scattered on the drum 31 or the dust on the copy sheets or in atmosphere.
A substantial high voltage is applied to a charge line of the transfer charger 33 to transfer the toner from the drum 31 to the copy sheets. The contamination of some or all of the charge line causes production of uneven or dim images, or of no images on copy sheets.
For preventing such phenomenon, a manual on the typical electrostatic machine instructs users to periodically brush off the transfer charger and the charge line. This is cumbersome and most users are inclined to ignore the instructions. Furthermore, it is particularly difficult to periodically brush off the charger and charge line in offices where lots of people use the machine. Generally, most people are liable to assume that the trouble is in the transfer charger and thereby raise a question about the quality of the machine and require a service technician to inspect the machine.